Fourth Assessment Report (AR4)

Fourth Assessment draft chapters and reviews


Terms of Access


In accordance with the Principles Governing IPCC Work, information on drafts of the contribution of Working Group II to the IPCC Fourth Assessment process, and review comments on these drafts are available for the duration of the AR5. The draft and comment files provided are intended as a record of the process used to prepare the Working Group II report. The information provided here are:

  • The first order draft chapters of the WG II report; review comments following the expert review of the first order drafts and corresponding author responses
  • The second order draft chapters; and expert and government review comments on the second order drafts and author responses
  • The draft Technical Summary (TS) and Summary for Policymakers (SPM) distributed with the second order draft chapters
  • The corresponding expert and government review comments and author responses;
  • The final distributed TS and SPM
  • Government comments on the final distributed draft SPM


Please note that government comments on the final distributed draft SPM were dealt with through the line by line approval process of the Eighth Working Group II Session that finalized the SPM in conjunction with coordinating lead authors and lead authors. Therefore, these files do not include author responses to these government comments.


Please also note that under IPCC procedures authors are required to take account of all substantive review comments in both review rounds. Thus responses to individual comments may be influenced by comments from other reviewers.


In accessing this material we ask that you agree to the following terms of use:


  • These review materials can be used for retrospective analysis or study of the report preparation process but drafts, review comments, and author responses are not to be represented as results of the IPCC assessment which are only defined by the final report (available through the link on the left).
  • These review materials are not to be altered nor redistributed.